I have a millermatic 175. The drive motor is very slow and does not have any torque. I have check the resistance on the wire speed knob, that seems to work fine. With the drive motor unhooked from the two wire connector I am getting 24 volts when I turn the wire speed knob all the way up and I think it was around 7 all the way down, at that connector. If i plug the motor back in and check the voltage at the motor I only get around 6 volts no matter where I set the wire speed. With the motor out and hooked to a 19.8 volt battery the motor spins as fast as I think it should. I don't have a lot off money to play with so I wanted to see if I could trouble shoot this my self before it goes to a shop.. Thanks for any input